Once the system is over water, environmental conditions are expected to be conducive for tropical cyclone formation, and a tropical depression is likely to develop by late Wednesday or Thursday while the system moves westward across the northern Gulf of Mexico. Tropical Storm Barry has a near 100 percent chance of forming, AccuWeather forecasters say, and, depending on the track it takes, the storm could flirt with becoming a hurricane before making landfall.
Potential storm surge has prompted the National Weather Service to issue a flood warning for the Mississippi River, including at New Orleans, through Saturday.
Regardless of the classification this system develops into, both Louisiana and MS are forecast to see very heavy rain - more than a foot in some places, Brink said. The city has 118 of its 120 pumps "available", the news release notes.
Some parts of downtown endured up to 10 inches of rain in a matter of hours while the cities of Harvey, Metairie, and Gretna were all reporting flooding. Clogged drains should be reported to 311.
As the low-pressure system moves closer to land, will meet warm, open waters that will fuel the storm's intensity, CNN meteorologist Haley Brink said. The heavy rain that created the flooding in New Orleans later tracked to the southwest, prompting an additional flash flood emergency for Jefferson Parish.
The National Weather Service said New Orleans is protected to a river level of 20 feet (6.1 meters), but it was forecast to rise above flood stage to 19 feet (5.8 meters) by Friday.
"Another concern is for wind associated with the storm", Kottlowski said.
Storm surge: the combination of a risky storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline.
Will storm Barry become a hurricane?
"This weekend looks to carry the most significant flooding threat for southern Louisiana, as what is expected to be Hurricane Barry by that time makes landfall in southwestern Louisiana", Sojda said.
Oil production companies operating in the Gulf of Mexico have also started to enact precautions.
Seas would turn dangerously rough for boaters and swimmers as the storm strengthens.
Beachgoers heading to the Gulf Coast this week could be greeted by the first tropical system to threaten the United States this year. A majority of the Euro (see Fig. 2) and GFS (see Fig. 3) ensemble members show a projected landfall of a strong topical storm somewhere between the upper-Texas coast and Louisiana by the weekend.